CVE-2021-22681: Rockwell Multiple Products Insufficient Protected Credentials Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
Rockwell Automation Studio 5000 Logix Designer Versions 21 and later, and RSLogix 5000 Versions 16 through 20 use a key to verify Logix controllers are communicating with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800. Rockwell Automation Studio 5000 Logix Designer Versions 21 and later and RSLogix 5000: Versions 16 through 20 are vulnerable because an unauthenticated attacker could bypass this verification mechanism and authenticate with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800.
Description quoted from the CVE record (assigned by icscert, published 2021-03-03).
Weakness: Insufficiently Protected Credentials CWE-522
How it can be exploited
Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: yes. Technical impact: total.
- On CISA KEV since
- 2026-03-05
- US federal deadline
- 2026-03-26
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: BDU:2021-01181, CNNVD-202102-1663, EUVD-2021-9817, EUVD-2024-47344, EUVD-2024-47439, GHSA-gq7m-h265-px53, GHSA-j8wv-5g58-r5vh, GHSA-pvh9-p4pw-h78q
Exploit Observer has no public exploit code that names this CVE or one of its aliases.
Vulnerability databases and vendor advisories (10)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2021-9817
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2024-47344
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2024-47439
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-gq7m-h265-px53
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-j8wv-5g58-r5vh
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-pvh9-p4pw-h78q
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2021-22681
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22681
- Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-202102-1663
- Vulnerability database or vendor advisory: https://www.tenable.com/cve/CVE-2021-22681
17 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.636
very likely to be attacked soon - VEDAS
- 0.935
strong exploit evidence - On CISA KEV
- Yes, since 2026-03-05
- Detection rule
- None yet
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Rockwell Automation Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers | version RSLogix 5000 Versions 16 through 20 version Studio 5000 Logix Designer: Versions 21 and later version CompactLogix 1768, 1769, 5370, 5380, 5480 version ControlLogix 5550, 5560, 5570, 5580 version DriveLogix 5560, 5730, 1794-L34 version Compact GuardLogix 5370, 5380 version GuardLogix 5570, 5580 version SoftLogix 5800 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: rockwell_automation_inc. rslogix_5000, rockwell_automation_inc. studio_5000_logix_designer, rockwellautomation rslogix_5000, rockwellautomation studio_5000_logix_designer.
How to fix it
CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vendor guidance:
- https://support.rockwellautomation.com/app/answers/answer_view/a_id/1130301/~/cve-2021-22681%3A-authentication-bypass-vulnerability-found-in-logix-controllers-
- https://www.cisa.gov/news-events/ics-advisories/icsa-21-056-03
- https://nvd.nist.gov/vuln/detail/CVE-2021-22681
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22681 (government-resource)
Other references
- https://us-cert.cisa.gov/ics/advisories/icsa-21-056-03 (x_refsource_MISC)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.